1- Resolva as expressões:

a) 5 + ( 3 - 1)=

b) ( 13 - 4 ) - 8 =

c) ( 20 - 3) + (7 + 5) =

d) 5 - [ 3+ ( 2 - 5)]=

e) 3 - [ 5- ( 4 - 6)]=

f) { 5 - [ 32 - (50 - 20) ]}=